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Impact of input parameters on the quality of mixing dispersion of nanoparticles
Cederová, Kristýna ; Hela, Rudolf (referee) ; Bodnárová, Lenka (advisor)
The bachelor thesis deals with nanoparticles. It examines the process of dispersion of nanoparticles in particular. Nanoparticles have the ability to improve some physical properties of cement composite materials. One, but important obstacle for correct application of nanoparticles is its dispersion. The experimental part of the thesis is dedicated to the dispersion of nanoparticles. Properties of cement composites were set in a time of 7 and 28 days. Nanoparticles were examined under transmission electron microscope.
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The influence of parameters on the quality of the dispersion medium mixed nanoparticles
Kutová, Lenka ; Hela, Rudolf (referee) ; Bodnárová, Lenka (advisor)
The thesis deals with monitoring the characteristics of cement composite using nanoparticles. The theoretical part describes nanoparticles production, their characteristics and influence on cement composites, both in fresh and hardened state. In the practical part of the thesis physically-mechanical characteristics of cement composites with nanoparticles are determined. The microstructure of the composites was monitored on a scanning electron microscope for 1, 3, 7 and 28 days of maturing. And finally mechanical characteristics of the composite and the reference samples without nanoparticles were compared.
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Interlaminar fracture toughness of fiber reinforced plastics
Vodička, Vít ; Mališ, Michal (referee) ; Klement, Josef (advisor)
Cílem této diplomové práce je lépe porozumět konceptu únavového poškození damage tolerance zmapováním všech možných vlivů na lomovou houževnatost vláknového kompozitu s polymerní matricí. Toho je dosaženo provedením zkoušek za různých podmínek (např. změna parametrů měření, mód zatížení, pořadí vrstev a materiál) a monitorováním odlišností v šíření trhliny. Na základě dat získaných během těchto testů je určena lomová houževnatost. Potenciální rozdíly jsou zkonzultovány a porovnány s ostatními vzorky.
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Study of catalytic activity of ceramic perovskite materials for energy applications
Schlosser, Radek ; Cihlář, Jaroslav (referee) ; Cihlář, Jaroslav (advisor)
In this diploma thesis the preparation of ceramic catalytic materials was studied. They were studied by means of catalytic activity on powder samples and in a form of membrane as well. At first were multicomponent perovskite materials with the help of “glycine-nitride synthesis” synthesized. Two types of perovskite systems were prepared. First system was on the basis of nickelates LaNiO3 and the second one on the basis of cobaltites SmCoO3. Both of them were doped with aluminium and calcium. Ceramic powders were catalytic tested during reformed reaction. A part of powders was pressed with hydraulic biaxial press. Then the membranes were calcinated, sintered and polished. The membranes were tested to specify the catalytic activity. At first they were in hydrogen atmosphere reduced and afterwards came through the partial oxidation. The appearance of coke fibers on the surface was discussed.
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Effect of curing conditions on the properties of alkali activated slag
Rypák, Peter ; Bayer, Patrik (referee) ; Rovnaník, Pavel (advisor)
Combination of fine ground granulated slag with proper alkaline activator gives alkali-activated slag – a material with remarkable properties. Theoretical part of the thesis deals with summarizing basic informations about alkali-activated slag, its properties, production and utilization. It also follows research devoted to effects of curing of alkali activated slag and shrinkage-reducing admixtures on its properties. Objective of the experimental part is to determine the influence of curing conditions on the mechanical properties and microstructure of alkali-activated slag. These properties are also monitored in alkali-activated slag with carbon nanotubes and hydroxypropylmethylcellulose as an shrinkage-reducing admixtures.
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The use of micro and nanotechnology to develop ultra high strength and high performance concrete with special features
Vlč, Viktor ; Ťažký, Tomáš (referee) ; Hela, Rudolf (advisor)
The use of nanotechnology has become wide spread in all branches of science. Nanotechnology help us to understand microstructure and due to the world has started to produce new materials. One of many examples carbon nanotubes (CNTs). In diploma thesis I tried to find the way of successful introduction into concrete mixture. I was studying influence of CNTs and other nano particles and I was comparing them with referential samples (without CNTs). Also I tested the improvement of mechanical characteristics of concrete. The morphology of nano particles was studied using Scanning Electron Microscopy (SEM). The results show that introduction of nanoparticles to results in increasing strength and higher density. That is why High Performace Concrete so resistant and durable.
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Study of dispersion of carbon nanotubes in cement composites
Michnová, Kamila ; Hela, Rudolf (referee) ; Bodnárová, Lenka (advisor)
Carbon nanotubes have the ability to improve the mechanical and physical properties of cement composites. However, their introduction into industrial utilization is hampered by several obstacles. It primarily involves the effective incorporation into the cement matrix, health and ecological risks. The experimental part of the work deals with the dispersing carbon nanotubes in aqueous solution and their subsequent integration into the structure of the cement matrix.
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High-grade concrete using nanoparticles
Labaj, Martin ; Bodnárová, Lenka (referee) ; Hela, Rudolf (advisor)
The aim of this paper is to summarize and assess the possibility of using nanoparticles as additives in high performance concrete. These particles have the ability to improve the mechanical and physical properties of cement composites or even gave them brand new ones. Industrial use, however, is hampered by several obstacles. In particular, it is the task of effective incorporation of nanoparticles into the matrix, the health and environmental risks and, last but not least, the financial costs. The experimental part of the work deals with the first-mentioned problem, namely with dispersing carbon nanotubes in aqueous solution and their subsequent integration into the structure of cement mortar.
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Carbon nanotubes in building materials
Fialová, Barbora ; Bayer, Patrik (referee) ; Rovnaník, Pavel (advisor)
Carbon nanotubes (CNTs) has become of great interest for scientists in many disciplines. This study examines the effect of CNTs as nanosized reinforcement for metakaolin–based geopolymer. It was found out that the addition of CNTs considerably affects the compressive and flexural strength geopolymer samples. The influence of CNTs on microstructure was examined using mercury intusion porosimetry and scanning electron microscopy.
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